Low density parity check (LDPC) codes are channel codes used in forward error correcting (FEC) schemes. LDPC codes are well known for their good performance and have received a great deal of attention in recent years. This is due to their ability to achieve performance close to the Shannon limit, the ability to design codes which achieve high parallelization in hardware, and their support of high data rates. Consequently, many of the currently active telecommunication standards have LDPC codes in their physical layer FEC scheme. LDPC codes are considered to be the next-generation communication system encoding standard.
Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) code is based on a base matrix of an irregular QC-LDPC matrix, the base matrix being formed by columns and rows, the columns being dividable into one or more columns corresponding to punctured variable nodes (i.e. variable nodes corresponding to information bits which are used by the encoder but are not transmitted to or effectively treated as not received by the decoder) and columns corresponding to not-punctured (non-punctured) variable nodes, and the rows being dividable into high-density rows (i.e. rows having a weight which is above a first weight) and low-density rows (i.e. rows having a weight which is below a second weight, wherein the second weight is equal to or smaller than the first weight).
While known approaches to channel coding have proven to perform well for a wide variety of scenarios, there is still an ongoing research to provide sophisticated solutions that achieve high data throughput with decent encoding/decoding resources.